JP7287137B2 - LIQUID EJECTING APPARATUS, LIQUID EJECTING METHOD, AND PROGRAM - Google Patents

Description

The present invention relates to a liquid ejection apparatus, a liquid ejection method, and a program.

2. Description of the Related Art A liquid ejecting apparatus such as a liquid ejecting printer ejects ink from an ejection head having a nozzle row in which a plurality of nozzle holes for ejecting liquid such as ink is arranged, and deposits ink on a recording medium for each pixel to form an image, for example. to form

In such a liquid ejecting apparatus, a predetermined area of a recording medium is scanned with a nozzle row multiple times, and ink is deposited on the recording medium based on image data rendered according to an image to be formed for each scan. , a multi-scanning method for completing image formation in a predetermined area is known.

On the other hand, in the field of sign graphics such as advertisements that are displayed indoors or outdoors, in addition to process color inks such as black and yellow, auxiliary color (special color) inks that are different from process colors such as white and orange are used. There is known a liquid ejecting apparatus to be used (see, for example, Patent Document 1).

However, in the apparatus disclosed in Japanese Patent Laid-Open No. 2002-200010, there were cases where ink could not be applied appropriately to a predetermined area of the recording medium.

An object of the technology disclosed herein is to appropriately apply ink to a predetermined area of a recording medium.

A liquid ejecting apparatus according to an aspect of the disclosed technique has a nozzle array in which a plurality of nozzle holes for ejecting liquid are arranged in a sub-scanning direction intersecting a main scanning direction, and a liquid that adheres the liquid to a recording medium. The ejection device includes a first nozzle row group in which at least two nozzle rows for ejecting the liquid of a first color are arranged in the sub-scanning direction; A second nozzle row group in which at least two nozzle rows for ejecting the liquids of two colors are arranged in the main scanning direction, the first nozzle row group, and the second nozzle row group. are scanned a plurality of times in the main scanning direction with respect to the recording medium, and the first nozzle array group and the second nozzle array group are scanned in the sub-scanning direction with respect to the recording medium and a sub-scanning unit that scans a plurality of times, and the first nozzle row group, in accordance with the scanning by the main scanning unit and the sub-scanning unit, to a plurality of pixels that constitute the first area of the recording medium. , the first ejection control section for depositing the liquid of the first color, and the second nozzle array group, according to the scanning by the main scanning section and the sub-scanning section, a second ejection control section for applying the liquid of the second color to a plurality of pixels forming a second area , wherein the first ejection control section is configured to apply the liquid to the first area; in the second scanning, the pixels to which the liquid of the first color has adhered in the first scanning are shifted by one pixel in the positive main scanning direction and by one pixel in the positive sub-scanning direction. The liquid of the first color is applied to a pixel-shifted position, and in the third scan, the negative main scan is applied to the pixel to which the liquid of the first color is applied by the second scan. The liquid of the first color is applied to a position shifted by one pixel in the direction and shifted by one pixel in the positive sub-scanning direction. The liquid of the first color is applied to a position shifted by one pixel in the positive main scanning direction and by one pixel in the positive sub-scanning direction with respect to the pixel to which the liquid is applied, In the second region, in the second scanning, the ejection control unit of 1 pixel in the positive main scanning direction with respect to the pixels to which the liquid of the second color has adhered in the first scanning. The liquid of the second color is deposited at a position shifted by one pixel in the positive sub-scanning direction, and the liquid of the second color is deposited by the second scanning in the third scan. The liquid of the second color is adhered to a position shifted by one pixel in the positive sub-scanning direction with respect to the pixels that have been drawn, and the liquid of the second color is applied by the fourth scan and the third scan. The liquid of the second color is deposited at a position shifted by one pixel in the negative main scanning direction and by one pixel in the positive sub-scanning direction with respect to the pixel to which the liquid of the second color is applied.

According to the disclosed technique, it is possible to appropriately adhere ink to a predetermined area of a recording medium.

1 is a diagram illustrating an example of a configuration of an image forming apparatus according to a first embodiment; FIG. 1 is an external view showing an example of the configuration of an image forming apparatus according to a first embodiment; FIG. 4A and 4B are diagrams illustrating an example of a configuration of an ejection head according to the first embodiment; FIG. 3 is a diagram showing an example of the configuration of a head unit according to the first embodiment; FIG. 3 is a diagram showing functional blocks of components of a control unit according to the first embodiment; FIG. FIG. 4 is a diagram showing an example of image formation by a multi-scanning method; FIG. 10 is a diagram for explaining a comparative example of an image forming method using a multi-scanning method; 4A and 4B are diagrams illustrating an example of an image forming method using a multi-scanning method according to the first embodiment; FIG. 6 is a flowchart showing an example of processing of a control unit according to the first embodiment; FIG. 5 is a diagram showing a modification of the configuration of the head unit according to the first embodiment; It is a figure which shows the component of the control part which concerns on 2nd Embodiment with a functional block.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments for carrying out the invention will be described with reference to the drawings. In each drawing, the same components are denoted by the same reference numerals, and redundant description may be omitted.

In the embodiments, an image forming apparatus that applies ink to paper by an inkjet method will be described as an example. An image forming apparatus is an example of a "liquid ejection apparatus", paper is an example of a "recording medium", and ink is an example of a "liquid".

In each drawing, the X direction indicated by an arrow indicates the main scanning direction, and the Y direction indicates the sub scanning direction that intersects with the main scanning direction.

[First embodiment]
FIG. 1 is a diagram showing an example of the configuration of an image forming apparatus according to this embodiment.

As shown in FIG. 1, the image forming apparatus 1 includes a head unit 2, a carriage section 3, a main scanning motor 4, a gear 5, a pressure roller 6, a timing belt 7, and a guide rod 8. , an encoder sensor 9 , an encoder sheet 10 and a platen 12 . The image forming apparatus 1 is a multi-scanning image forming apparatus in which the head unit 2 is caused to scan multiple times by the carriage section 3 .

The head unit 2 has a plurality of ejection heads and is fixed to the carriage section 3 . A plurality of ejection heads eject process color inks and auxiliary color inks. The process colors are four basic colors for image formation. The process color inks are, for example, black ink, cyan ink, magenta ink, and yellow ink. The auxiliary color inks are, for example, orange ink and green ink. A process color is an example of a "first color" and an auxiliary color is an example of a "second color". Auxiliary colors are an example of "colors other than yellow, magenta, cyan, and black." The configuration of the ejection head will be described in detail with reference to FIG. 2, and the configuration of the head unit 2 will be described in detail with reference to FIG.

The main scanning motor 4 transmits the driving force associated with the rotation to the carriage section 3 via the gear 5 , pressure roller 6 and timing belt 7 . The carriage unit 3 reciprocates (reciprocates) along the guide rod 8 in the main scanning direction (X direction). The reciprocating scanning of the carriage section 3 in the main scanning direction allows the head unit 2 to change its position in the main scanning direction.

The encoder sheet 10 has a linear scale that indicates the position in the main scanning direction. The encoder sensor 9 provided in the carriage portion 3 reads the linear scale of the encoder sheet 10 and detects the position in the main scanning direction when the carriage portion 3 scans in the main scanning direction.

On the other hand, the paper 11 is conveyed in the sub-scanning direction (Y direction) along a predetermined conveying path from the supply unit of the image forming apparatus 1 by the driving force associated with the rotation of a sub-scanning motor (not shown). position is reached.

The ejection head included in the head unit 2 ejects ink toward the paper 11 while scanning in the main scanning direction, and adheres the ink to the paper 11 . When one scan in the main scanning direction of the head unit 2 is completed, the paper 11 is conveyed by a predetermined amount in the sub-scanning direction. When the transport of the paper 11 in the sub-scanning direction is completed, the ejection head provided in the head unit 2 ejects ink toward the paper 11 while scanning in the main scanning direction, and adheres the ink to the paper 11 .

By repeating the scanning of the head unit 2 in the main scanning direction, the conveyance of the paper 11 in the sub-scanning direction, and the ejection of ink by the ejection head according to these scanning and transportation, the ink is printed on the paper 11. , for example, a color image is formed.

The ejection head provided in the head unit 2 can eject ink toward the paper 11 while scanning in at least one of the positive main scanning direction and the negative main scanning direction.

FIG. 2 is an external view showing an example of the configuration of the image forming apparatus according to this embodiment. In FIG. 2, the carriage section 3, the main scanning motor 4, the guide rod 8, the platen 12, and the sub-scanning motor 121 provided in the image forming apparatus 1 are shown.

FIG. 3 is a diagram showing an example of the configuration of the ejection head according to this embodiment. FIG. 3 is a plan view of the ejection head viewed from the ink ejection direction.

The ejection head 21 has a nozzle plate 17 . A plurality of nozzle holes 16 are arranged at equal intervals in the sub-scanning direction in the nozzle plate 17 . In the example of FIG. 3, 64 nozzle holes 16 are provided in the sub-scanning direction to form a nozzle row. Further, four such nozzle rows are provided in the main scanning direction.

Each nozzle row is shifted in the sub-scanning direction by half the distance between the nozzle holes 16 with respect to the adjacent nozzle row. In other words, the nozzle rows are staggered. By staggering the nozzle rows, the density (resolution) of image formation in the sub-scanning direction can be improved.

The ejection head 21 ejects ink from each nozzle hole. Further, the ejection head 21 ejects different colors of ink for each nozzle row.

FIG. 4 is a diagram showing an example of the configuration of the head unit 2 according to this embodiment. FIG. 4 is a plan view of the head unit 2 viewed from the ink ejection direction.

The head unit 2 has an ejection head 211 , an ejection head 212 , and an ejection head 213 . Each of the ejection heads 211 to 213 has the same configuration as the ejection head 21 described with reference to FIG.

In the head unit 2, the ejection head 211 is arranged on the most positive main scanning direction side and the most negative sub scanning direction side among the three ejection heads. The ejection head 211 has a nozzle row group 211o and a nozzle row group 211g. The nozzle row group 211o has a nozzle row 211o1 and a nozzle row 211o2, and the nozzle row group 211g has a nozzle row 211g1 and a nozzle row 211g2.

The nozzle row 211o1 ejects orange ink, which is one of the auxiliary colors, from 64 nozzle holes arranged in the sub-scanning direction. The nozzle row 211o2 is provided at a position apart from the nozzle row 211o1 in the positive main scanning direction, and ejects orange ink from each of 64 nozzle holes arranged in the sub-scanning direction.

The nozzle row 211g1 is provided at a position apart from the nozzle row 211o2 in the positive main scanning direction, and ejects green ink, which is one of the auxiliary colors, from 64 nozzle holes arranged in the sub-scanning direction. Dispense. The nozzle row 211g2 is provided at a position away from the nozzle row 211g1 in the positive main scanning direction, and ejects green ink from each of 64 nozzle holes arranged in the sub-scanning direction.

The ejection head 212 is arranged in the head unit 2 at a position shifted to the negative main scanning direction side and the positive sub-scanning direction side with respect to the ejection head 211 . The ejection head 212 has a nozzle row 212y, a nozzle row 212c, a nozzle row 212m, and a nozzle row 212k.

The nozzle row 212y ejects yellow ink, which is one of the process colors, from 64 nozzle holes arranged in the sub-scanning direction. The nozzle row 212c is provided at a position apart from the nozzle row 212y in the positive main scanning direction, and ejects cyan ink, which is one of the process colors, from the nozzle holes arranged in the sub-scanning direction. .

The nozzle row 212m is provided at a position away from the nozzle row 212c in the positive main scanning direction, and each of the 64 nozzle holes arranged in the sub-scanning direction discharges magenta ink, which is one of the process colors. to dispense. The nozzle row 212k is provided at a position apart from the nozzle row 212m in the positive main scanning direction, and ejects black ink, which is one of the process colors, from the nozzle holes arranged in the sub-scanning direction. .

In the head unit 2, the ejection head 213 is arranged on the most negative main scanning direction side and the most positive sub scanning direction side among the three ejection heads. The ejection head 213 has a nozzle row 212y, a nozzle row 212c, a nozzle row 212m, and a nozzle row 212k. Since the configuration and function of each nozzle row are the same as those of the ejection head 212, description thereof will be omitted.

The nozzle row groups 211o and 211g of the ejection head 211 are examples of the "second nozzle row group". It is also an example of the “first nozzle row group” of the nozzle row group having the nozzle row 212 y and the nozzle row 213 y of the ejection head 212 . Similarly, a nozzle row group having the nozzle row 212c and the nozzle row 213c, a nozzle row group having the nozzle row 212m and the nozzle row 213m, and a nozzle row group having the nozzle row 212k and the nozzle row 213k are referred to as "first This is an example of the "nozzle array group".

As shown in FIG. 4, the ejection head 212 is arranged at a position shifted from the ejection head 211 in the sub-scanning direction, and the ejection head 213 is arranged at a position shifted from the ejection head 212 in the sub-scanning direction. be done. With such an arrangement, it is possible to expand the range in which ink is applied to the paper 11 in the sub-scanning direction in one scan of the head unit 2 in the main scanning direction.

At both ends of each of the ejection heads 211 to 213 in the sub-scanning direction, there are no-nozzle areas in which no nozzle holes are formed. For example, as shown in FIG. 4, the length in the sub-scanning direction of the no-nozzle region at one end of the ejection head 211 is defined as length 2111, and the length in the sub-scanning direction of the no-nozzle region at one end of the ejection head 212 is defined as Let the length be 2121 . The ejection head 212 is arranged so as to overlap with the ejection head 211 in the sub-scanning direction by at least a length equal to or greater than the sum of the lengths 2111 and 2121 . In addition, the ejection head 212 is displaced from the ejection head 211 in the negative main scanning direction. By arranging them in this way, even when the ejection heads 211 to 213 are displaced in the sub-scanning direction as described above, there are areas in the sub-scanning direction where ink does not adhere to the paper 11 due to the non-nozzle areas. can be prevented. Such arrangement and its effect are the same for the arrangement of the ejection head 213 with respect to the ejection head 212 .

Next, FIG. 5 is a diagram showing the constituent elements of the control unit 100 according to this embodiment in functional blocks. Note that the functional blocks of the control unit 100 shown in FIG. 5 are conceptual, and need not be physically configured as shown. All or part of each functional block can be functionally or physically distributed and combined in arbitrary units. All or any part of each processing function performed by each functional block can be implemented by a program executed by the CPU of the control unit 100, or by hardware based on wired logic.

For example, the control unit 100 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), etc., and the CPU cooperates with the RAM to execute a program stored in the ROM. , the function of each part is realized. Also, the processing executed by the CPU may be executed by an electronic circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array).

The control unit 100 includes a system control unit 101, an ejection cycle signal generation unit 102, a memory control unit 103, an image data storage unit 104, a carriage control unit 105, a process color ejection control unit 106, and an auxiliary color ejection control unit. 107 and a paper transport control unit 108 .

The control unit 100 also includes a driving unit 200 that drives the ejection head 211 , a driving unit 300 that drives the ejection head 212 , a PC (Personal Computer) 400 , an operation panel 109 , a main scanning motor 4 , an encoder sensor 9 is electrically connected to

The PC 400 inputs image data for image formation on the paper 11, sets the resolution of image formation by the image forming apparatus 1, and transmits image data and instructions for controlling the image forming apparatus to the control unit 100. FIG. The PC 400 includes a RIP (Raster Image Processor) section 401 and a rendering section 402 . A RIP (Raster Image Processor) unit 401 executes image processing according to a color profile and user settings.

Here, in the multi-scanning method, for each scan of the head unit 2, ink is applied to predetermined pixels among a plurality of pixels forming 11 predetermined regions of the paper. Pixels to which ink is applied for each scan of the head unit 2 are specified based on the rendering data.

The rendering unit 402 decomposes the image data into rendering data for each scan of the head unit 2 . At this time, the rendering unit 402 sets pixels to which ink is applied as valid data and pixels to which ink is not applied as invalid data, and generates thinned data having valid data and invalid data.

The thinned-out data is, for example, binary image data in which valid data is "1" and invalid data is "0". By integrating the thinned-out data and the image data, it is possible to specify pixels to which ink is to be applied for each scan.

The rendering unit 402 generates thinned data for process colors and thinned data for auxiliary colors as thinned data, and outputs the thinned data to the system control unit 101 .

The system control unit 101 receives image data and commands transmitted from the PC 400 . Also, an operation signal is input from the user via the operation panel 109 provided in the image forming apparatus 1 . The operation of the image forming apparatus 1 is controlled according to these.

The image data storage unit 104 is a memory that temporarily stores image data received by the system control unit 101 . The memory control unit 103 controls input and/or output of image data to the image data storage unit 104 .

Based on the output signal of the encoder sensor 9 and the image forming resolution set by the user, the ejection cycle signal generation unit 102 generates a signal indicating the timing at which the ejection heads 211 to 213 eject ink in synchronization with the movement of the carriage unit 3. to generate

The process color ejection control unit 106 inputs the process color thinning data generated by the rendering unit 402 via the system control unit 101 and the memory control unit 103 . The process color ejection control unit 106 causes the ejection heads 212 and 213 to eject process color inks at pixels corresponding to valid data of the image data input from the memory control unit 103 based on the process color thinning data.

The auxiliary color ejection control unit 107 inputs auxiliary color thinning data generated by the rendering unit 402 via the system control unit 101 and the memory control unit 103 . The auxiliary color ejection control unit 107 causes the ejection head 211 to eject auxiliary color ink at pixels corresponding to valid data of the image data input from the memory control unit 103 based on the auxiliary color thinning data.

The operations of the process color ejection control unit 106 and the auxiliary color ejection control unit 107 will be separately described in detail with reference to FIGS. The process color ejection control unit 106 is an example of a "first ejection control unit", and the auxiliary color ejection control unit 107 is an example of a "second ejection control unit".

The process color ejection control unit 106 and the auxiliary color ejection control unit 107 can also perform ejection control for each nozzle row.

The carriage control section 105 drives the main scanning motor 4 based on the output signal of the encoder sensor 9 to control the position of the carriage section 3 in the main scanning direction. The carriage control unit 105 is an example of a "main scanning unit".

The paper transport control unit 108 drives the sub-scanning motor 121 according to a command from the system control unit 101, transports the paper 11 in the sub-scanning direction, and controls the position of the paper 11 in the sub-scanning direction. By transporting the paper 11 in the sub-scanning direction, the paper transport control unit 108 can cause the carriage unit 3 to relatively scan the paper 11 in the sub-scanning direction. The paper transport control unit 108 is an example of a "sub-scanning unit".

The drive unit 200 has a drive waveform data storage unit 201 , a drive waveform generation unit 202 , a DAC (Digital Analog Converter) 203 , a voltage amplification unit 204 , a current amplification unit 205 and a cooling fan control unit 206 . The drive unit 200 drives the ejection head 211 to eject the auxiliary color ink. For example, the ejection head 211 has a piezoelectric member that expands and contracts with applied voltage, and the drive unit 200 drives the piezoelectric member to eject the auxiliary color ink.

The drive waveform data storage unit 201 stores the waveform of the voltage signal for driving the ejection head 211 as drive waveform data.

The drive waveform generation unit 202 generates a drive waveform corresponding to the droplet size of the ink to be ejected based on the drive waveform data. For example, if the drive waveform data includes three pulse waveforms corresponding to droplets, the drive waveform generation unit 202 generates a drive waveform in which two of the three pulse waveforms are invalidated when ejecting droplets. Further, the drive waveform generation unit 202 generates a drive waveform in which one of the three pulse waveforms is disabled when ejecting a medium droplet, and generates a drive waveform in which all three pulse waveforms are enabled when ejecting a large droplet. .

DAC 203 converts the drive waveform from a digital voltage to an analog voltage. The converted analog drive waveform is amplified in voltage by the voltage amplifier 204 and amplified in current by the current amplifier 205 , and is input to the ejection head 211 .

The cooling FAN control unit 206 is electrically connected to the thermistor 207 included in the ejection head 211 and the cooling FAN 208 . The cooling FAN control unit 206 controls the temperature of the ejection head 211 by driving the cooling FAN 208 based on a signal indicating the temperature detected by the thermistor 207 . As a result, it is possible to suppress the change in the viscosity of the auxiliary color ink filled in the ejection head 211 due to the temperature rise.

The drive unit 300 includes a drive waveform data storage unit 301, a drive waveform generation unit 302, a DAC 303, a voltage amplification unit 304, a current amplification unit 305, and a cooling fan control unit 306, and drives the ejection head 212. to eject the process color ink. For example, the ejection head 212 has a piezoelectric member that expands and contracts with applied voltage, and the drive unit 300 drives the piezoelectric member to eject process color ink.

The drive waveform data storage unit 301 has the same function as the drive waveform data storage unit 201 , the drive waveform generation unit 302 has the same function as the drive waveform generation unit 202 , and the DAC 303 has the same function as the DAC 203 . The function of the voltage amplifier 304 is the same as that of the voltage amplifier 204, the function of the current amplifier 305 is the same as that of the current amplifier 205, and the function of the cooling fan controller 306 is the same as that of the cooling fan controller 206. . Therefore, description of these will be omitted.

The control unit 100 is also connected to and controls the drive unit of the ejection head 213, but since it is the same as the control of the drive unit 300 of the ejection head 212, illustration and description thereof are omitted.

Although FIG. 5 shows a configuration in which the rendering unit 402 is included in the PC 400 , the control unit 100 may have the function of the rendering unit 402 . Similarly, the control section 100 may have the function of the RIP section 401 . Also, the control unit 100 may have some or all of the functions of the driving unit 200 , or may have some or all of the functions of the driving unit 300 .

Here, the multi-scanning method will be described. 2. Description of the Related Art In an inkjet image forming apparatus, ink is ejected onto a sheet of paper 11, and the ink that lands on the sheet of paper 11 adheres to the sheet of paper 11 to form pixels. When the resolution of image formation is high, the interval between adjacent pixels is shortened, so that a phenomenon occurs in which the adjacent inks landed on the paper 11 are merged. Note that coalescence means that adjacent liquids such as ink are combined to form one, and two pixels are combined, resulting in image noise.

In order to prevent such coalescence of ink on the paper 11, in the multi-scanning method, the ink is made to land on the paper 11 by dividing it into multiple scans of the head unit 2, and between adjacent pixels, Gives a time lag to ink landing.

For example, if ink is landed on one adjacent pixel immediately after the other ink is landed, both inks will be in a state where they are not dry, so they will be attracted to each other and wet and spread, and coalescence will occur. There is However, if a time lag is given, the ink in one pixel dries and hardens before the other ink lands, so when the other ink lands, it is not pulled by the other ink and spreads out. This prevents coalescence of ink in adjacent pixels.

In the multi-scanning method, the head unit 2 scans a predetermined area of the paper 11 a plurality of times, and ink is ejected based on rendering data for each scan to complete image formation on the predetermined area.

FIG. 6 is a diagram showing an example of image formation by the multi-scanning method. FIG. 6A shows an example of image data that is the basis of image formation. Each of the plurality of circles shown in FIG. 6A represents a pixel and corresponds to a plurality of pixels forming a predetermined area of the paper 11. FIG. In imaging, ink is applied to each such pixel.

FIG. 6(b) shows rendering data for each scan. scan1 is rendering data representing an image formed by the first scan. A white circle indicates a pixel where ink is ejected and adheres to the paper 11 . A black circle indicates a pixel where no ink is ejected and no ink adheres to the paper 11 . A number "1" inside a white circle indicates a pixel to which ink adheres in the first scan.

scan2 is rendering data representing an image formed by the second scan. Similarly, white circles indicate pixels to which ink is ejected and ink adheres to the paper 11, and the number "2" inside the white circle indicates pixels to which ink adheres in the second scan.

scan3 is rendering data representing an image formed by the third scan. The number "3" inside the white circle indicates the pixel to which the ink adheres in the third scan.

scan4 is rendering data representing an image formed by the fourth scan. The number "4" inside the white circle indicates the pixel to which the ink adheres in the fourth scan.

FIG. 6(c) shows an image formed by ink adhering to a predetermined area of the paper 11. FIG. As shown in FIG. 6(b), when ink is applied to each pixel in sequence for each scan, an image is formed in a predetermined area of the paper 11 as shown in FIG. 6(c).

Note that FIG. 6 shows an example of rendering data in which 3/4 of the image data are pixels to which ink does not adhere, and ink is applied to 1/4 of each pixel in one scan, but the present invention is not limited to this. . The rendering unit 402 can generate appropriate rendering data according to the resolution of image formation and the sequence of image formation.

Next, a comparative example of this embodiment will be described with reference to FIG. FIG. 7 shows a process using the head unit 2 shown in FIG. are attached in the same order. For example, the process color ink is yellow ink and the auxiliary color ink is orange ink.

In FIG. 7, the ejection head 211 ejects auxiliary color ink in the same manner as shown in FIG. A hole and four nozzle holes of the nozzle row 211o2 are shown. Similarly, ejection heads 212 and 213 eject process color inks in the same manner as shown in FIG. Four nozzle holes of 213y are shown.

FIG. 7 shows an example in which auxiliary color ink is ejected from one nozzle hole of the nozzle row 211o1 of the ejection head 211 and one nozzle hole of the nozzle row 211o2. Also, an example in which process color ink is ejected from one nozzle hole of the nozzle row 212 y of the ejection head 212 is shown.

The squares shown to the right of the ejection heads 211 to 213 represent the pixels of the image formed on the paper 11. FIG.

A pixel region 220 shown corresponding to the ejection head 211 is a pixel region to which the ejection head 211 deposits the auxiliary color ink. The black squares are pixels to which the auxiliary color ink has adhered, and the numbers shown in the squares indicate the number of scans in which the auxiliary color ink has adhered. Two nozzle holes of the ejection head 211 form an 8-pixel image with auxiliary color ink.

A pixel region 230 shown corresponding to the ejection head 212 is a pixel region to which the ejection head 212 deposits process color ink. The gray squares are pixels to which the process color ink has adhered, and the numbers shown in the squares indicate how many times the process color ink has adhered. One nozzle hole of the ejection head 212 forms an 8-pixel image with process color ink.

Scan1 to Scan8 shown in the upper part of the figure indicate the number of scans. For example, in FIG. 7, below "Scan1", the pixels to which the auxiliary color inks are applied and the pixels to which the process color inks are applied in the first scan are shown in association with each other. Similarly, below "Scan1" to "Scan8", the pixels to which the auxiliary color ink is applied and the pixels to which the process color ink is applied in each scan are shown in association with each other.

In the first scan (Scan1), the ejection head 211 deposits the auxiliary color ink on two pixels as shown, and the ejection head 212 deposits the process color ink on one pixel as shown. .

In the second scan (Scan2), the ejection head 211 shifts each pixel to which ink was applied in the first scan by one pixel in the positive main scanning direction and one pixel in the positive sub-scanning direction. Apply auxiliary color ink. Similarly, the ejection head 212 deposits process color ink on pixels shifted by one pixel in the positive main scanning direction and by one pixel in the positive sub-scanning direction from each pixel to which ink was deposited in the first scan.

In the third scan (Scan3), the ejection head 211 shifts each pixel to which ink has been deposited in the second scan by one pixel in the negative main scanning direction and one pixel in the positive sub-scanning direction. Apply auxiliary color ink. Ink has already adhered to this position in the first scan, but the ink in the third scan is superimposed thereon. Similarly, the ejection head 212 deposits process color ink on pixels shifted by one pixel in the negative main scanning direction and by one pixel in the positive sub-scanning direction from each pixel deposited with ink in the second scan.

In the fourth scan (Scan4), the ejection head 211 shifts each pixel to which ink has been deposited in the third scan by one pixel in the positive main scanning direction and one pixel in the positive sub-scanning direction. Apply auxiliary color ink. This position already has ink from the second scan, and is overlaid with ink from the fourth scan. Similarly, the ejection head 212 deposits process color ink on pixels shifted by one pixel in the positive main scanning direction and by one pixel in the positive sub-scanning direction from each pixel to which ink is deposited in the third scan.

Here, since the auxiliary color ink is ejected from two nozzle holes, it should adhere to eight pixels in four scans. Since the pixels to which is attached are overlapped, ink is not attached to all of the eight pixels.

Next, in the fifth scan (Scan5), the ejection head 211 deposits the auxiliary color ink on pixels shifted by one pixel in the positive sub-scanning direction from the pixels to which ink was deposited in the fourth scan. . Similarly, the ejection head 212 deposits the process color ink on pixels shifted by one pixel in the positive sub-scanning direction with respect to each pixel deposited with ink in the fourth scan.

Note that since the paper 11 is conveyed only in the negative sub-scanning direction, in the fifth scan, pixels shifted by one pixel in the negative sub-scanning direction with respect to the pixels to which ink was adhered in the fourth scan. Not attached. Therefore, to be precise, for example, of the eight pixels to which the auxiliary color ink is applied in FIG. 7, the upper right pixel does not have the ink applied, and the ink is applied to the pixel 221 indicated by the dashed line. However, for ease of viewing, FIG. 7 shows the ink applied to pixel 221 in the upper right pixel of the eight pixels. The same applies to the process color ink by the ejection head 212 .

Next, in the sixth scan (Scan6), the ejection head 211 shifts by one pixel in the negative main scanning direction and by one pixel in the positive sub-scanning direction with respect to each pixel to which ink is deposited in the fifth scan. Auxiliary color ink is applied to the pixels that have been read. Similarly, the ejection head 212 deposits process color ink on pixels shifted by one pixel in the negative main scanning direction and by one pixel in the positive sub-scanning direction from each pixel deposited with ink in the fifth scan.

By scanning 6 times, the auxiliary color ink adheres to all 8 pixels.

In the seventh scan (Scan7), the ejection head 212 shifts each pixel to which ink has been deposited in the sixth scan by one pixel in the positive main scanning direction and one pixel in the positive sub-scanning direction. Apply process color ink.

In the eighth scan (Scan8), the ejection head 212 shifts each pixel to which ink has been applied in the seventh scan by one pixel in the negative main scanning direction and one pixel in the positive subscanning direction. Apply process color ink.

In this way, the ejection head 212 can apply the process color ink to eight pixels by scanning eight times, for example, using one nozzle hole of the nozzle row 212y. Since the ejection head 213 operates in the same manner, one nozzle hole of the ejection head 212 and one nozzle hole of the ejection head 213 can be used to apply the process color ink to a total of 16 pixels in eight scans. .

On the other hand, the ejection head 212 uses, for example, one nozzle hole in the nozzle row 211o1 and one nozzle hole in the nozzle row 211o2 to deposit the auxiliary color ink on eight pixels in four scans, and the process color ink. Similarly, it is necessary to apply auxiliary color ink to 16 pixels in 8 scans. However, if the auxiliary color inks are ejected in the same ejection order as the process color inks, the positions of the pixels to which the inks adhere overlap between the first and third scans, and between the second and fourth scans, as described above. Therefore, it is not possible to apply ink to 8 pixels in 4 scans using 2 nozzle holes.

Therefore, if the auxiliary color inks are ejected with the same number of scans as the ejection of the process color inks, the auxiliary color inks cannot be applied to the same number of pixels as the process colors, resulting in missing pixels. On the other hand, if pixel dropouts are to be prevented, the number of scans must be increased accordingly (for example, scanning should be performed six times instead of four), resulting in a longer image forming time.

Here, an example of the ink adhesion method according to this embodiment will be described with reference to FIG. In FIG. 8, the head unit 2 shown in FIG. 4 is used to apply one process color ink and one auxiliary color ink to a plurality of pixels forming a predetermined area of the paper 11 by a multi-scanning method. An attached example is shown. However, in contrast to the comparative example described in FIG. 7, in FIG. 8, the process color ink and the auxiliary color ink are applied in different orders to the pixels for each scan.

Since the number of nozzles in the ejection head in FIG. 8 and how to view the squares representing pixels are the same as in FIG. 7, the description thereof will be omitted.

In FIG. 8, in the first scan (Scan1), the ejection head 211 deposits the auxiliary color ink on two pixels as shown, and the ejection head 212 deposits the process color ink on one pixel as shown. Apply ink.

In the second scan (Scan2), the ejection head 211 shifts each pixel to which ink was applied in the first scan by one pixel in the positive main scanning direction and one pixel in the positive sub-scanning direction. Apply auxiliary color ink. Similarly, the ejection head 212 deposits process color ink on pixels shifted by one pixel in the positive main scanning direction and by one pixel in the positive sub-scanning direction from each pixel to which ink was deposited in the first scan.

In the third scan (Scan3), the ejection head 211 deposits the auxiliary color ink on the pixels shifted by one pixel in the positive sub-scanning direction from the pixels to which the ink was deposited in the second scan. The ejection head 212 deposits the process color ink on pixels shifted by one pixel in the negative main scanning direction and by one pixel in the positive sub-scanning direction from each pixel deposited with ink in the second scan.

Note that since the paper 11 is conveyed only in the negative sub-scanning direction, in the third scan, pixels shifted by one pixel in the negative sub-scanning direction with respect to the pixels to which ink was adhered in the second scan. Not attached. Therefore, to be precise, for example, of the eight pixels to which the auxiliary color ink is applied in FIG. 8, the upper right pixel does not have the ink applied, and the ink is applied to the pixel 222 indicated by the dashed line. However, for ease of viewing, the ink deposited on pixel 222 is shown in the upper right pixel of the eight pixels in FIG.

In the fourth scan (Scan4), the ejection head 211 shifts each pixel to which ink was applied in the third scan by one pixel in the negative main scanning direction and one pixel in the positive sub-scanning direction. Apply auxiliary color ink. The ejection head 212 deposits the process color inks on the pixels shifted by one pixel in the positive main scanning direction and by one pixel in the positive sub-scanning direction with respect to the pixels to which the ink was applied in the third scan.

Here, unlike the example described with reference to FIG. 7, the auxiliary color ink does not overlap the pixels to which the ink adheres in each scan, so ink adheres to all eight pixels in four scans.

The order in which the ejection head 212 applies the process color ink to each pixel after the fifth scan (Scan5) is the same as that described with reference to FIG.

In this way, the ejection head 212 can apply the process color ink to eight pixels by scanning eight times, for example, using one nozzle hole of the nozzle row 212y. Since the ejection head 213 operates in the same manner, one nozzle hole of the ejection head 212 and one nozzle hole of the ejection head 213 can be used to deposit the process color ink on a total of 16 pixels in eight scans.

On the other hand, the auxiliary color inks are also ejected in a different order than the process color inks. Auxiliary color ink can be applied to eight pixels. The auxiliary color ink can be attached to 16 pixels by scanning 8 times. In this way, the auxiliary color inks can be applied to the same number of pixels as the process colors with the same number of scans as the process color inks. There is no need to increase the number of scans, and an increase in image forming time and ink consumption can be prevented.

In FIG. 8, the pixel region 230 is an example of the "first region", and the order of applying the process color inks by the ejection head 212 to the plurality of pixels forming the pixel region 230 of the paper 11 is as follows. This is an example of the "first order". In FIG. 8, the pixel region 220 is an example of the "second region", and the order in which the ejection head 211 applies the auxiliary color ink to the plurality of pixels forming the pixel region 220 of the paper 11 is " This is an example of "second order".

FIG. 9 is a flowchart showing an example of processing by the control unit 100 according to this embodiment.

First, the carriage control section 105 drives the main scanning motor 4 based on the output signal of the encoder sensor 9 to scan the carriage section 3 in the main scanning direction and move the head unit 2 to a position in the main scanning direction ( step S91).

Next, while the head unit 2 is moving, the process color ejection control unit 106 drives the ejection heads 212 and 213 so that a plurality of pixels forming the first region of the paper 11 are printed in the first order. Process color ink is applied along the line (step S92).

While the head unit 2 is moving, the auxiliary color ejection control unit 107 drives the ejection head 211 to apply the auxiliary color ink to the plurality of pixels forming the second region of the paper 11 in the second order. It is made to adhere (step S93).

The system control unit 101 determines whether one scan in the main scanning direction has been completed (step S94).

If one scan in the main scanning direction has not been completed (step S94, No), the process returns to step S91. When one scan in the main scanning direction is completed (step S94, Yes), the paper transport control unit 108 drives the sub-scanning motor 121 to transport the paper 11 in the sub-scanning direction. It is moved to a predetermined position in the sub-scanning direction (step S95). By transporting the paper 11 in the sub-scanning direction, the paper transport control unit 108 can cause the carriage unit 3 to relatively scan the paper 11 in the sub-scanning direction.

The system control unit 101 determines whether one scan in the sub-scanning direction has been completed (step S96).

If one scan in the sub-scanning direction has not been completed (step S96, No), the process returns to step S95. When one scan in the sub-scanning direction is completed (step S96, Yes), the system control unit 101 determines whether image formation on a predetermined area of the paper 11 is completed (step S97).

If the image formation on the predetermined area of the paper 11 is not completed (step S97, No), the process returns to step S91. When the image formation of the predetermined area of the paper 11 is completed (step S97, Yes), the control section 100 ends the process.

In this manner, the image forming apparatus 1 can form an image on a predetermined area of the paper 11 under the control of the control section 100 .

Effects of the image forming apparatus of this embodiment will be described. In a liquid ejecting apparatus using auxiliary color ink, the auxiliary color ink is used less frequently than the process color ink, so the number of ejection heads for the auxiliary color ink is reduced with respect to the number of ejection heads for the process color ink. Sometimes.

For example, as described above, among ejection heads having a predetermined number of nozzle rows, only one ejection head is used for ejecting auxiliary color inks, and the other plurality of ejection heads are used for ejection of process color inks. is. In this case, for example, two nozzle rows are arranged in the main scanning direction for one ejection head to eject one auxiliary color ink, and two nozzle rows are arranged to eject one process color ink. One nozzle row is arranged in the sub-scanning direction with respect to the head. By arranging the nozzle rows in this way, the number of nozzle holes for ejecting one auxiliary color ink is equal to the number of nozzle holes for ejecting one color of process color ink. Therefore, if appropriate, the process color ink and the auxiliary color ink can be applied to the same number of pixels with a predetermined number of scans. In some cases, the auxiliary color ink could not be applied properly.

In this embodiment, according to the scanning, process color inks are applied in a first order to a plurality of pixels forming the first area of the paper 11, and a plurality of pixels forming the second area of the paper 11 are applied. Pixels are inked in a second order with auxiliary colors. This prevents overlapping of pixels to which the auxiliary color ink adheres in each scan, and image formation with the same number of pixels in the same number of scans can be performed for the process color and the auxiliary color.

Image formation with auxiliary colors can be completed without increasing the number of scans, and an increase in image formation time can be prevented. In addition, in a multi-scanning liquid ejection device using auxiliary color inks, the auxiliary color inks can be appropriately applied to a predetermined area of the recording medium.

Here, FIG. 10 is a diagram showing a modification of the configuration of the head unit according to this embodiment. FIG. 10 is a plan view of the head unit 2a viewed from the ink ejection direction.

The head unit 2 a has an ejection head 215 and an ejection head 216 . Each of the ejection heads 215 and 216 has the same configuration as the ejection head 21 described with reference to FIG.

In the head unit 2, the ejection head 215 is arranged on the most positive side in the main scanning direction and on the most negative side in the sub-scanning direction among the two ejection heads. The ejection head 215 has a nozzle row group 215o, a nozzle row 215y, and a nozzle row 215m. The nozzle row group 215o has a nozzle row 215o1 and a nozzle row 215o2.

The nozzle row 215y ejects yellow ink, which is one of the process colors, from 64 nozzle holes arranged in the sub-scanning direction. The nozzle row 215m is provided at a position away from the nozzle row 215y in the positive main scanning direction, and each of the 64 nozzle holes arranged in the sub-scanning direction discharges magenta ink, which is one of the process colors. to dispense.

The nozzle row 215o1 is provided at a position away from the nozzle row 215m in the positive main scanning direction, and orange ink, which is one of the auxiliary colors, is supplied from each of the 64 nozzle holes arranged in the sub-scanning direction. to dispense. The nozzle row 215o2 is provided at a position apart from the nozzle row 215o1 in the positive main scanning direction, and ejects orange ink from each of 64 nozzle holes arranged in the sub-scanning direction.

The ejection head 216 is arranged in the head unit 2 at a position shifted to the positive sub-scanning direction side with respect to the ejection head 215 on the negative main scanning direction side. The ejection head 216 has a nozzle row 216y, a nozzle row 216c, a nozzle row 216m, and a nozzle row 216k.

The nozzle row 216y ejects yellow ink, which is one of the process colors, from 64 nozzle holes arranged in the sub-scanning direction. The nozzle row 216c is provided at a position apart from the nozzle row 216y in the positive main scanning direction, and ejects cyan ink, which is one of the process colors, from nozzle holes arranged in the sub-scanning direction. .

The nozzle row 216m is provided at a position apart from the nozzle row 216c in the positive main scanning direction, and each of the 64 nozzle holes arranged in the sub-scanning direction discharges magenta ink, which is one of the process colors. to dispense. The nozzle row 216k is provided at a position apart from the nozzle row 216m in the positive main scanning direction, and ejects black ink, which is one of the process colors, from the nozzle holes arranged in the sub-scanning direction. .

The nozzle row group 215o of the ejection head 215 is an example of the "second nozzle row group". Further, the nozzle row group having the nozzle row 215y and the nozzle row 216y of the ejection head 216 is an example of the "first nozzle row group", and the nozzle row group having the nozzle row 215m and the nozzle row 216m is This is an example of the "first nozzle row group".

As shown in FIG. 4, the ejection head 212 is arranged at a position shifted from the ejection head 211 in the sub-scanning direction, and the ejection head 213 is arranged at a position shifted from the ejection head 212 in the sub-scanning direction. be done. By arranging in this way, it is possible to expand the range in which ink is applied to the paper 11 in the sub-scanning direction by one scan in the main scanning direction of the head unit 2 .

Since the mutual positional relationship of the ejection heads 215 and 216 is the same as that of the ejection heads 211 to 213 in the head unit 2, description thereof is omitted.

Using the ejection head 215, the auxiliary color ink is ejected onto the paper 11 by the method described with reference to FIG. 8, and the ejection head 216 is used to eject the process color ink onto the paper 11 by the method described with reference to FIG. , the same effects as when the head unit 2 is used can be obtained.

[Second embodiment]
Next, a liquid ejection device according to a second embodiment will be described. Note that the description of the same components as those of the already described embodiment will be omitted.

In the first embodiment, process color inks are applied in a first order and auxiliary color inks are applied in a second order to a plurality of pixels forming a predetermined area of the paper 11 according to scanning. Specifically, for example, in the third scan, the process color ejection control unit 106 controls one pixel in the negative main scanning direction and one pixel in the positive The process color ink was deposited at a position shifted by one pixel in the scanning direction. On the other hand, in the third scan, the auxiliary color ejection control unit 107 applies the auxiliary color ink at a position shifted by one pixel in the positive sub-scanning direction from the pixels to which the auxiliary color ink was applied in the second scan. attached.

In this embodiment, the second order in which the auxiliary color inks are applied can be changed. For example, in the third scan, the auxiliary color ejection control unit 107 can change the position shifted by one pixel in the positive sub-scanning direction from the pixel to which the auxiliary color ink was applied in the second scan to another position. do.

FIG. 11 is a diagram showing functional blocks of the components of the control unit 100a according to the present embodiment. The control unit 100 a has an ejection order changing unit 110 . The ejection order changing unit 110 changes the order (an example of the second order) in which the auxiliary color ejection control unit 107 deposits the auxiliary color ink for each scan on a plurality of pixels forming a predetermined area of the paper 11 . .

For example, in the head unit 2, there is a case where the arrangement of the nozzle row that ejects the auxiliary color ink and the nozzle row that ejects the process color ink is changed. Depending on the arrangement of the nozzle rows, the proper order of applying the auxiliary color inks to the paper 11 may change.

In the present embodiment, by providing the ejection order changing unit 110, the order in which the auxiliary color inks are applied to the paper 11 is changed according to the arrangement of the nozzle arrays for ejecting the auxiliary color inks and the nozzle arrays for ejecting the process color inks. can be made appropriate.

Effects other than the above are the same as those described in the first embodiment.

Although the liquid ejecting apparatus according to the embodiments has been described above, the present invention is not limited to the above embodiments, and various modifications and improvements are possible within the scope of the present invention.

In the above-described embodiment and modification, the case of auxiliary color ink has been described as an example. Color ink may not adhere properly. The embodiments and modifications can also be applied in such cases, and the process color inks can be appropriately applied to predetermined areas of the recording medium.

This embodiment also includes a liquid ejection method and a program. For example, the liquid ejection method includes a liquid ejection device that has a plurality of nozzle rows in which nozzle holes for ejecting liquid are arranged in a sub-scanning direction that intersects the main scanning direction, and that adheres the liquid to a recording medium, A first nozzle array group in which at least two nozzle arrays for ejecting the liquid of the first color for image formation are arranged in the sub-scanning direction, and a second nozzle array group different from the first color. and a second nozzle row group in which at least two nozzle rows for ejecting the liquid of a color are arranged in the main scanning direction, wherein the first nozzle comprises: a step of scanning the recording medium with the row group and the second nozzle row group a plurality of times in the main scanning direction; a step of scanning a recording medium a plurality of times in the sub-scanning direction; a step of depositing the liquid of the first color in a first order on a plurality of pixels constituting the accordingly, depositing the liquid of the second color on a plurality of pixels forming a second region of the recording medium in a second order different from the first order.

Further, the program includes a liquid ejecting apparatus having a plurality of nozzle rows in which nozzle holes for ejecting liquid are arranged in a sub-scanning direction intersecting the main scanning direction, and for applying the liquid to a recording medium. a first nozzle row group in which at least two nozzle rows for ejecting the liquid of the first color are arranged in the sub-scanning direction; and a second nozzle row group in which at least two nozzle rows for ejecting liquid are arranged in the main scanning direction, the program being executed by a liquid ejection device, wherein the first nozzle row group and a process of scanning the recording medium with the second nozzle array group multiple times in the main scanning direction, and scanning the first nozzle array group and the second nozzle array group with the recording medium. , a first region of the recording medium is configured according to scanning by the main scanning unit and the sub scanning unit by the process of scanning a plurality of times in the sub scanning direction and the first nozzle array group. a process of depositing the liquid of the first color in a first order on a plurality of pixels that and applying the liquid of the second color to a plurality of pixels forming a second area of the recording medium in a second order different from the first order.

According to such a liquid ejection method and program, it is possible to obtain the same effect as the liquid ejection apparatus described above.

1 Image forming apparatus (an example of a liquid ejecting apparatus)
2 head units 211 to 213 ejection heads 211o and 211g nozzle row group (an example of a second nozzle row group)
212y, 212c, 212m, 212k nozzle rows 213y, 213c, 213m, 213k nozzle rows 200, 300 driving unit 220 pixel region (an example of the second region)
230 pixel area (an example of the first area)
3 carriage unit 4 main scanning motor 121 sub-scanning motors 100 and 100a control unit 101 system control unit 105 carriage control unit (an example of a main scanning unit)
106 process color ejection control unit (an example of the first ejection control unit)
107 auxiliary color ejection control unit (an example of a second ejection control unit)
108 Paper transport control unit (an example of sub-scanning unit)
110 discharge order changing unit (an example of a changing unit)
402 Rendering Unit

JP 2017-217810 A

Claims (9)

A liquid ejecting apparatus having a nozzle row in which a plurality of nozzle holes for ejecting liquid are arranged in a sub-scanning direction intersecting a main scanning direction, the liquid ejecting apparatus applying the liquid to a recording medium,
a first nozzle row group in which at least two of the nozzle rows for ejecting the liquid of the first color are arranged in the sub-scanning direction;
a second nozzle row group in which at least two nozzle rows for ejecting the liquid of a second color different from the first color are arranged in the main scanning direction;
a main scanning unit that scans the recording medium with the first nozzle array group and the second nozzle array group a plurality of times in the main scanning direction;
a sub-scanning unit that scans the recording medium with the first nozzle array group and the second nozzle array group a plurality of times in the sub-scanning direction;
The liquid of the first color is applied to a plurality of pixels forming a first area of the recording medium by the first nozzle array group according to the scanning by the main scanning section and the sub-scanning section. a first ejection control unit to be deposited ;
The liquid of the second color is applied to a plurality of pixels forming a second area of the recording medium by the second nozzle array group according to the scanning by the main scanning section and the sub-scanning section. and a second ejection control unit for adhering ,
In the first region, the first ejection control unit is configured to:
In the second scan, the pixels to which the liquid of the first color is adhered in the first scan are shifted by one pixel in the positive main scanning direction and by one pixel in the positive sub-scanning direction. depositing the liquid of the first color on the position of the first color;
In the third scan, the pixels to which the liquid of the first color is adhered in the second scan are shifted by one pixel in the negative main scanning direction and by one pixel in the positive sub-scanning direction. depositing the liquid of the first color on the position of the first color;
In the fourth scan, the pixels to which the liquid of the first color is adhered in the third scan are shifted by one pixel in the positive main scanning direction and by one pixel in the positive sub-scanning direction. depositing the liquid of the first color on the position of the first color;
In the second region, the second ejection control unit is configured to:
In the second scanning, the pixels to which the liquid of the second color is adhered in the first scanning are shifted by one pixel in the positive main scanning direction and by one pixel in the positive sub-scanning direction. depositing the liquid of the second color on the position of the second color;
In the third scan, the liquid of the second color is applied to a position shifted by one pixel in the positive sub-scanning direction from the pixel to which the liquid of the second color is adhered by the second scan. attach,
In the fourth scan, the pixels to which the liquid of the second color is adhered in the third scan are shifted by one pixel in the negative main scanning direction and by one pixel in the positive sub-scanning direction. depositing the liquid of the second color on the
Liquid ejection device. 2. The liquid ejecting apparatus according to claim 1, wherein the first nozzle row group and the second nozzle row group are provided at different positions in the sub-scanning direction. The first nozzle row group is
the nozzle row provided at a position different from the second nozzle row group in the sub-scanning direction;
2. The liquid ejecting apparatus according to claim 1, further comprising the nozzle row provided at the same position as the second nozzle row group in the sub-scanning direction. The sub-scanning section conveys the recording medium in the sub-scanning direction, and scans the recording medium with the first nozzle array group and the second nozzle array group a plurality of times in the sub-scanning direction. 4. The liquid ejecting apparatus according to any one of claims 1 to 3. the first nozzle row group has the nozzle rows that eject the liquid of at least one color of yellow, magenta, cyan, and black;
5. The liquid ejecting apparatus according to claim 1, wherein the second nozzle array group includes nozzle arrays for ejecting the liquid in colors other than yellow, magenta, cyan, and black. The liquid ejection device forms an image based on input image data,
6. The liquid ejection according to any one of claims 1 to 5 , further comprising a rendering section that decomposes the image data into a plurality of pieces of rendering data that form an image for each scan by the main scanning section and the sub-scanning section. Device. 7. The liquid ejecting apparatus according to any one of claims 1 to 6 , further comprising a changing section that changes the order in which the liquid is applied by the second ejection control section . A liquid ejecting apparatus having a nozzle row in which a plurality of nozzle holes for ejecting liquid are arranged in a sub-scanning direction intersecting a main scanning direction, the liquid ejecting apparatus applying the liquid to a recording medium,
The liquid ejecting apparatus includes a first nozzle array group in which at least two nozzle arrays for ejecting the liquid of a first color are arranged in the sub-scanning direction;
a second nozzle row group in which at least two nozzle rows for ejecting the liquid of a second color different from the first color are arranged in the main scanning direction;
has
a step of scanning the recording medium with the first nozzle row group and the second nozzle row group a plurality of times in the main scanning direction by a main scanning unit;
a step of scanning the recording medium with the first nozzle row group and the second nozzle row group a plurality of times in the sub-scanning direction by a sub-scanning unit;
The first ejection control section causes the first nozzle array group to apply the above-mentioned ink to a plurality of pixels forming a first region of the recording medium according to the scanning by the main scanning section and the sub-scanning section. depositing said liquid of a first color;
The second ejection control unit causes the second nozzle array group to apply the above-mentioned ink to a plurality of pixels forming a second region of the recording medium according to the scanning by the main scanning unit and the sub-scanning unit. depositing said liquid of a second color ;
In the first region, the first ejection control unit is configured to:
In the second scan, the pixels to which the liquid of the first color is adhered in the first scan are shifted by one pixel in the positive main scanning direction and by one pixel in the positive sub-scanning direction. depositing the liquid of the first color on the position of the first color;
In the third scan, the pixels to which the liquid of the first color is adhered in the second scan are shifted by one pixel in the negative main scanning direction and by one pixel in the positive sub-scanning direction. depositing the liquid of the first color on the position of the first color;
In the fourth scan, the pixels to which the liquid of the first color is adhered in the third scan are shifted by one pixel in the positive main scanning direction and by one pixel in the positive sub-scanning direction. depositing the liquid of the first color on the position of the first color;
In the second region, the second ejection control unit is configured to:
In the second scanning, the pixels to which the liquid of the second color is adhered in the first scanning are shifted by one pixel in the positive main scanning direction and by one pixel in the positive sub-scanning direction. depositing the liquid of the second color on the position of the second color;
In the third scan, the liquid of the second color is applied to a position shifted by one pixel in the positive sub-scanning direction from the pixel to which the liquid of the second color is adhered by the second scan. attach,
In the fourth scan, the pixels to which the liquid of the second color is adhered in the third scan are shifted by one pixel in the negative main scanning direction and by one pixel in the positive sub-scanning direction. depositing the liquid of the second color on the
Liquid ejection method. A program for causing a liquid ejecting apparatus, which has a plurality of nozzle rows in which nozzle holes for ejecting liquid are arranged in a sub-scanning direction intersecting a main scanning direction, to adhere the liquid to a recording medium to execute a process, comprising:
The liquid ejecting apparatus includes a first nozzle array group in which at least two nozzle arrays for ejecting the liquid of a first color are arranged in the sub-scanning direction;
a second nozzle row group in which at least two nozzle rows for ejecting the liquid of a second color different from the first color are arranged in the main scanning direction;
has
a process of scanning the recording medium with the first nozzle array group and the second nozzle array group a plurality of times in the main scanning direction by a main scanning unit;
a process of scanning the recording medium with the first nozzle array group and the second nozzle array group a plurality of times in the sub-scanning direction by a sub-scanning unit;
The first ejection control section causes the first nozzle array group to apply the above-mentioned ink to a plurality of pixels forming a first region of the recording medium according to the scanning by the main scanning section and the sub-scanning section. applying said liquid of a first color;
The second ejection control unit causes the second nozzle array group to apply the above-mentioned ink to a plurality of pixels forming a second region of the recording medium according to the scanning by the main scanning unit and the sub-scanning unit. a process of depositing the liquid of a second color;
In the first region, the first ejection control unit is configured to:
In the second scan, the pixels to which the liquid of the first color is adhered in the first scan are shifted by one pixel in the positive main scanning direction and by one pixel in the positive sub-scanning direction. depositing the liquid of the first color on the position of the first color;
In the third scan, the pixels to which the liquid of the first color is adhered in the second scan are shifted by one pixel in the negative main scanning direction and by one pixel in the positive sub-scanning direction. depositing the liquid of the first color on the position of the first color;
In the fourth scan, the pixels to which the liquid of the first color is adhered in the third scan are shifted by one pixel in the positive main scanning direction and by one pixel in the positive sub-scanning direction. depositing the liquid of the first color on the position of the first color;
In the second region, the second ejection control unit is configured to:
In the second scanning, the pixels to which the liquid of the second color is adhered in the first scanning are shifted by one pixel in the positive main scanning direction and by one pixel in the positive sub-scanning direction. depositing the liquid of the second color on the position of the second color;
In the third scan, the liquid of the second color is applied to a position shifted by one pixel in the positive sub-scanning direction from the pixel to which the liquid of the second color is adhered by the second scan. attach,
In the fourth scan, the pixels to which the liquid of the second color is adhered in the third scan are shifted by one pixel in the negative main scanning direction and by one pixel in the positive sub-scanning direction. a program for depositing the liquid of the second color on the position where the second color is placed .

Images